In today's digital audio/visual (A/V) systems, it is quite common for a device to be in communication with multiple other devices and to accordingly have a number of inputs in order to accommodate communications with the multiple other devices. Accordingly, multiple data signaling paths may exist between multiple digital A/V devices, herein referred to as modules, which may include a set-top box (STB) or set-back box (SBB), a DVD player, a PC, a video game system, an A/V receiver, and a compatible digital audio and/or video monitor device, such as a television (TV) or a digital television (DTV) to facilitate communications between the multiple modules and a TV.
The data signal paths provided by multiple interfaces between devices of an A/V system can and do vary in protocol and number. For example, a TV or DTV may communicate via multiple data signaling paths to the various modules connected to it, including High Definition Multimedia Interface (HDMI®) CEC, HDMI I2C, HDMI Video, Universal Serial Bus (USB), Ethernet (wired or wireless), IEEE 1394 (so-called firewire™ or i-link™), Bluetooth, and RF. HDMI®, for instance, is a digital audio/visual connector interface capable of transmitting uncompressed and compressed streams, and can provide an interface between any compatible digital audio/video (A/V) source device, or module, and a compatible digital audio and/or video monitor device, such as a TV. Using HDMI, audio, visual, status and control information may be transmitted via one cable in the system. Consumer Electronic Control (CEC) is a protocol used to control devices that are attached using HDMI. CEC features, as may be defined from time to time in the CEC Specification, include routing control, standby, system information, and feature abort.
There can be problems attendant with such input/output devices communicating with multiple other devices (modules) via various signaling paths or interfaces. One concern is that of mis-wiring. In the case of a TV in communication with potentially many different modules, each module can use a variety of signaling path interfaces to communicate with the TV, including HDMI CEC, HDMI Video, HDMI I2C, and USB2, for example, and mis-wiring is a common concern when there are many ways to connect the modules to the TV. For instance, a user of the system can plug-in module, such as a STB or SBB using a HDMI #1 connector but then use a USB2 #2 connector. If multiple modules are used, this situation may confuse the TV.
In addition, there is also the concern of hackers trying to gain unauthorized access to the communication interface(s) between system devices. The greater the number of modules attached to the TV, for instance, the greater the number of paths that may be attacked and thus the greater the concern.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.